With Milestone 6 reached, Husk gains some new features:
The milter process which encrypts passing emails never tries to fetch updates for used certificates, but stays with the one it initially downloaded. That way however the milter will miss important updates to a certificate (like its revocation). Husk now features a updater process which will periodically (and randomly) fetch updates for local certificates.
When encrypting an email, the milter uses the preferences of the used certificate to determine the output format of the encrypted email. This means that certificates advertising OpenPGPv6 capabilities will lead to encrypted emails in OpenPGPv6 format - which are undecryptable if the used software only understands OpenPGPv4. The milter can now be forced to generate encrypted emails in OpenPGPv4 format even if the used certificate offers OpenPGPv6 capabilities.
Other notable new developments (besides optimizations and fixes):